Raiding

As resources in Shra are scarce and the harsh environment can often cut people off from them, they frequently set out to steal or plunder rather than trade. Surprise attacks, bringing little risk and potentially good loot, are favored by Shra warriors. The most desirable prizes are portable, like camels, cattle, slaves and luxury goods.

Conquest

Outright conquest and the establishment of states is very rare in Shra and always temporary. Most oasis settlements are protected by sturdy stone walls that are impossible to breach without some siege equipment. This requires attackers to drag that across the desert and then settle down for a potentially long siege, with the defenders having a very strong advantage in water and food supplies. Therefore almost all sieges fail.
Should invaders manage to conquer a settlement, then their hold on it is often precarious. Population density is low, distances large and communication difficult, breaking down almost completely during summer and winter. Conquerors lack the numbers to establish anything more than small garrisons, which may be overwhelmed by vengeful natives.

Strategic layout

Many wars are fought between humans and surre, though at least as many among tribes of humans and surre themselves. The constant warfare has made Shra a patchwork of racial confederations. Neither of the anthropoid races have dominance over all luxury resources, so they are forced to trade, though they sometimes raid too.
The only place where the two races mix is in the Ighrb Tim. There the west is predominantly human and the east surre. To be able to venture outside of the valley humans had to pass through surre territory. Warfare used to be constant in the past, until the economy nearly collapsed and peace had to be made. Since then, the people of the valley have learned to live next to each other and even mix in the two large oases.
Humans and surre are distributed over Shra in a pattern that resembles an irregular checkerboard. This distribution has varied a little over time, but in broad strokes is centuries old. As many conflicts are fought along racial lines, this helps to keep the settlements in a state of nearly constant strife.

Armor and weapons

In the extreme climate of Shra, adaptation to temperature is at least as important for armor as protection against attacks. Shra armor is mostly made of cloth or leather. Warriors wear multiple suits over each other, increasing them in cold and removing them in heat. The use of metal is very rare and limited to coarse scale armor.
Likewise, the use of metal in weapons is rare too. Common weapons are bow and arrow, javelin, spear, club, mace and axe. Their handles are made of wood, the tips of flint, chert, obsidian, copper or bronze. Because both metal and wood are expensive, the most popular weapon of all is the sling. Though a difficult weapon to master, use of the sling is taught from a young age, producing very capable missile troops.

Camel cavalry

There are no horses on Shra. The only animal that can be used in combat is the camel. It is not so fast as a horse, some 20 kilometers per hour in a 10 minute race to 30 kilometers per hour in a short furious charge. Still, it is big and high and strong, so warriors sometimes use camels as heavy cavalry to break infantry formations. More often, they fight as light missile cavalry, armed with slings, javelins or bows.